Pneumatic lifting jack



Jun 29 1926.. 1,590,830

S. JEWKES PNEUMATIC LIFTING JACK Filed March 14, 1925 v 2 Sheets-Sheet 1June 29 1926.

. S. JEWKES PNEUMATIC LIFTING JACK 2 Sheets-Sheet 2 Filed March 14, 1925Patented June 29, 1926;

"UNITED STATES "PATENTyOFFICE.

SPENCER JEWKES, or SYDNEY, NEW SOUTH WALES, AUSTRALIA.

- PNEUMATIC LIFTING JACK.

Application filed March 14,1325, Serial No. l5, 543,"and in AustraliaMarch.2 0, 1924.

This invention relates to an improved pneumatically operated liftingjack particularly adapted for automobile use, whereby a vehicle can beconveniently raised to facilitateremoval. repair or adjustment of itsparts. The object of the invention is to provide apneumatic lifting jackof relatively simple. construction. which can be easily and rapidlyoperated and having improved means for gradually releasing the gaspressure, thus enabling a vehicle sup-' ported by the lifting jack to beslowly lowcred without shock to its normal running position.

According to the invention I provide a lifting jack comprising a basehaving a cylindrical casing in which a piston is vertically slidable.This piston has a tubular piston rod wherein is fitted an adjustable ramhaving-a jack head at its upper end. Fitted in the base of the liftingjack is a gas inlet valve, preferably of the nipple type, which isconnected by a small gas inlet pipe to said cylindrical casing at abeneath the piston. Said inletvalve is also connected by a flexible tubeto a holder. which is adapted to accommodate a small compressed gasbulb, and has a piercer against which said gas bulb is forced 'by meansof a pressure screw.

The lifting jack has a handle, preferably formed in detachable sections,in which a valve operating rod is mounted. This valve operating rodi'sarranged to actuate a slow release gas valve accommodated in the baseof the lifting jack and connected to the cylindrical casing by a gasoutlet pipe.

Thelifting jack may be provided with a safety valve to automaticallyfunction under excessive gas pressure, and said safety valve ispreferably arranged between the end of the flexible tube connected tothe gas container holder and the of the lifting jack. 1

The invention is illustrated in the accompanying drawings wherein Figure1 is a view in perspective of a representative form of my invention.

Figure 2 is a vertical cross-sectional view of the lifting jack seen. inFigure 1.

Figure. 3 is; a horizontal cross-sectional viewon-line 3-3 of Figure 2.'Q

Figure 4 is a sectional detail view of the holder for the compressed gasbulb and the point gas inlet valve associated means for piercing saidgas bulb to supply gas under pressure beneath the piston.

Figure 5 is a sectional view illustrating the handle construction andthe operating rod for actuating the gas release valve.

Figure 6 shows detail views of the gas release valve, and the lower endof the handle of the lifting jack.

Figure 7 is a sectional detail View of the safety valve forautomatically releasing excessive gas pressure.

Figure 8 is a vertical cross-sectional view of a modified form oflifting jack within the invention. I

In these views, 5 indicates the base of the pneumatic lifting jack whichis preferably constructed of cast metal and has ribs 6 formed on itsunderneath surface to prevent the lifting jack fromslipping or movingwhile it is in use. Formed integrally 'with said base is a verticalcylindrical cas ing 7 having a screwed cap or cover 8 fitted over itsupper end.

S lidably mounted in the cylindrical casing 7 is a piston 9. which hasa-packing disc 10 formed of leather,rrubber or like material to providea-gas-tight, but yet sliding fit between said piston and the sur-' faceof the cylindrical casing 7. The piston rod 11 is of tubular formationand is ver tically slidable, in a guide boss 12 formed on the cover. 8.

Fitted in said tubular piston rod 11 is a ram 13, which is of tubularconstruction andhas a jack head 14 detachably fitted into its upperend.- This ram is vertically adjustable within the tubular piston rod11, and for the purpose of retaining it in selected adjusted position itis provided with a series of oppositely disposed adjustment holes 15,through which a pin 16 can be readily passed. The pin 16 is attached toa chain 17 which is fastened tothe cover 8, to prevent liability ofmisplacement. The upper end of the piston rod 11 is formed with aplurality of grooves 18 which register with the series of adjustmentholes 15 in the ram 13 and which receive the pm 16 in order to preventit from slipping while the lifting jack is in use.

Fitted in the base 5' of the lifting ack 1s a gas inlet valve 19,preferably of the'nipple type, which is connectedby a small gas inletpipe 20 to the cylindrical casing 7 at a point eneath the piston 9. Theinner end of the gas inlet pipe 20 is upturned as at 21; and it projectsabove the surface level of "a quantity of lubricating oil, such ascastor oil, which is contained in the bottom of the cylindrical casing7.

The gas inlet valve 19 is connected by a flexible tube 22 to a holder23, which is adapted to detachably support a small compressed gas bulb24, preferably of the sparklet type having a readily puncturable forwardend. The gas container holder 23 has a pressure screw 25, which isadapted to exert pressure upon the rear end of the gas bulb 24 supportedin said holder, and force the forward puncturable end of same against agrooved piercer 26, which is sup ported in a casing 27 connected to theflexible tube 22 and screwed into the end of the said holder 23.

Fitted in the casing 27 of the holder 23 and surrounding the piercer 26is an annular washer 28 formed of rubber or like material. which isadapted to form a gas-tight iit against the forward puncturable end ofthe gas container 24, when same is pressed against the piercer 26 by thepressure screw 25. The annular washer 28 and the piercer 26 are bothheld tightly in position within the casing 27 by means of a screwednipple 29. The casing 27 has a tubular end 30 which, by allowing freecirculation of air around the end of the flexible tube 22. preventsfreezingof the escaping gas from the gas container 24. and thus preventsany blockage of the tube 22.

Between the flexible pipe 22 and the gas inlet valve 19, there may bearranged a safety relief valve 31, which is adapted to automaticallyrelease excessive pressureof gas within the tube 22 and prevent damagebeing caused to the integers of the lifting jack This relief valve.which is illustrated in detail in Figure 7, comprises a valve casing 32having a valve seat 33 and an internally screw-threaded valve chamber34. Slidably mounted in a nut member 35 screwed into said valve chamberis a valve stem 36 having a valve head 37 hearing against said valveseat- 33. A coiled spring 38 surrounds the valve stem 36. and it bearsagainst the nut member 35 and the valve head 37 to by means of a gasoutlet pipe 41 having an upturned inner end 42 arranged adjacent to theend 21 of the gas inlet pipe 20. Said gas release valve 40. which isillustrated particularly in igure 6, comprises a casing 43 formed with ashoulder 44, against which is seated a block 45 having angular gaspassages or grooves 46. Slidably fitted in said block 45 is a valve-stem47, upon which is fixedly secured a valve head 48 that is adapted toclose against a valve seat 49 provided upon a sleeve 50 having centralgas passages or grooves (not shown). coiled spring 51 encircles thevalve stem 47. and it normally maintains the valve head 48 closedagainst the valve seat 49.

Fitted into the valve housing 39 on the base 5 by means of a bayonetconnect-ion 52 is a handle 53. which consists of two tubular sections 54and 55 detachably connected togcther by a bayonet connection 56 having acoiled locking spring 57. The lower end of the handle section 54 fitsover the end of the valve casing 43see Figure 6-and it also has a-coiled s1n'ing 58 hearing against its end to maintain the bayonetconnection 52 in correct locking position.

Arranged within the tubular handle sec.- tions is a valve operating rod59 that is formed in two sections slidably mounted in guide blocks 60.The lower end of said valve operating rod 59 abuts against the end ofthe valve stem 47 while its upper end functions as a press button byprojecting outwardly from a hand grip 61 which is fitted to the end ofthe upper handle section 55.

lVhcn the lifting jack is required for use, i

the handle 53 and other detachable parts are fitted onto the liftingjack. and the jack is then arranged in correct position by means of saidhandle beneath the axle or other integer of an automobile to be raised.The ram 13 is then adjusted within the tubular piston rod 11. so that;the jack head 14 is arranged in position against and beneath the vehicleaxle or other part. when the pin 16 is inserted through aconvenientadjustment hole 15 to retain said ram m adjusted position.

A gas bulb 24 of the type described and containin carbon-dioxide gas orother suitable gas undcr high pressure is then fitted into the holder 23and the-pressure screw 25 is operated to cause the forward puncturableend of said gas bulb to be forced tightly passes through'the flexibletube 22 to the gas inlet valve 19 and thence through said valve alongthe gas inlet pipe 20 into the cylindrical casing 7 at a point beneaththe, piston 9. Any excessive gas pressure within the flexible tube 22 isautomatically rejack-head 14 to rise and thus raise the ve'- hicle todesired height for adjustment, re-

upon which is fitted a packing discmoval or repair of its parts.

When it is'required to release the gas pressure within the lifting jackto enable a vehicle supported thereby to be again lowered to correctrunning position. the valve operating rod 59 is depressed by exertingfinger pressure onits projecting button end, causing the valve stem 47of ,the gas release valve40 to be moved downwardly against the influenceof its coiled spring 51. The valve head 48 is thus moved away, from the"alve seat 49- allowing the gas under pressure in the cylindrical casing7 to pass through the gas outlet pipe 41 and through the gas passages orgrooves 46 in the block into the valve casing 43, whence it passesthrough the valve seat 49, and escapes through. the central passage inthe sleeve 50 into the tubular handle 53. The release valve 40 is of theslow acting type and. allows the gas to escape very gradually so thatthe vehicle supported by the lifting jack is slowly lowered to itsnormal running position without any shock.

During the operation of the lifting jack,

cylindrical casing 7 over the interior surface.

of said casing and over the surfaces of the piston 9, thus effectivelylubricating the lifting jack and also providing a-gas-tight seat whichprevents escape of the compressed gas from said casing. When the liftingjack is not "required for use, the flexible tube 22' is unscrewed fromthe gas inlet valve 18, the handle 53 is detached and its sections 54and 55 are dismantled for convenience in storage.

In the modified form of the invention illustrated 'by Figure 8, atubular member 62 is screwed into the base 5 of the liftingjack over theends of the 'gas'inlet and outlet pipes 20 and 41, respectively, andsaid tubular memberis formed with a flange 63,

Slidably mounted in said tubular member 62 is a ram of hollowconstruction, whichover said valve casin has a jack head 66 fitted intoits upper end. This ram 65 is formed integrally with a cylindricalcasing 67, which is slidable on the flange 63 and the packing disc 64,and it has a cap 68 fitted toits lower end. This cap. has a centralguide aperture 69, through which passes the tubular member 62. Thepacking disc 64 is designed to hold a quantity of lubricating oil, whichserves to lubribricate the lifting jack during use.

In. this arrangement. when gas under pressure is admitted into thelifting jack through the gas'inlet pipe 20, it exerts pres sure againstthe closed end of the ram 65 and also passes upwardly through the spacebetween said ram and the tubular member 62 into the cylindrical casing67 arranged above the flange 63 and the packing disc 64. The gas thuscauses said ram 65 and the cylindrical casing 67 to be forced upwardly,

sliding upon the tubular member 62, thus bringing the jack head 66 intoengagement with the axle or other part of the vehicle and raising thevehicle to a. required height for the purpose that is necessary.

A lifting jack according to this form of the invention is furnished witha gas bulb holder and a flexible connecting tube similar to theconstruction illustrated in Figures 1 to 7 and it also has a detachablehandle having means for operating the gas release valve.

It is'tn be understood that in a pneumatic lifting jack according to theinvention, the gas bulb means herein described for supplying compressedgas to the cylindrical casing of the lifting jack may be dispensed with,and in lieu thereof an 'inflating pump may be employed oralternativelymeans may be provided whereby compressed air can be supplied fromstorage containers such as are provided in garages and likeestablishments.

Vhat I do claim is:-

1. A pneumatic lifting jack, comprising a casing provided with a gasinlet; a piston slidable vertically in the casing; a jack head movablewith the piston; means for supplying gas under pressure to said inlet; agas release valveconnected to said casing; an elongated tubular handlefitting over the release valve; and a rod slidablein said handle foroperating said valve.

2. A pneumatic lifting jack, comprising a casing provided with a gasinlet; a piston slidable vertically in the casing; a jack head movablewith the piston; means for, supplying gas under pressure to said inlet;a

against which the valve head is normally held; an elongated tubularhandle fitting and a rod slidable in said handle and bearing againstsaid valve stem to operate the same.

3. A pneumatic lifting ]ack, comprlsmg a casing provided with a gasinlet; a piston slidable vertically in the casing; a jack head,

against which the valve head is normally.

held; an elongated tubular handle fitting over said valve casing; and arod slidablein said handle and hearing at its inner end against thevalve stem to operate. the same, the outer end of said rod projectingbeyond the handle to form an exposed pushmember.

4. A pneumatic lifting ja ek. eon'iprising a easing provided with a gasinlet; a piston slidable vertically in the easing; a jack head movablewith the piston; means for supplyi-nggas under pressure to said inlet; agas release valve eonneeted to said casing; an elongated tubular handlefitting over the release valve: and a rod slidable in the handle and havine its inner end operatively related to said valve, the outer end ofsaid rod projecting beyond the handle to form an exposed pusl1n1en1ber.

In testimony whereof I aflix my signature.

SPENCER J EW KES.

